The IORteam

IOR Screening Consultancy (MAESTRO)

Introduction

Full evaluation of Improved Oil Recovery potential within even a modest field portfolio is a massive task, requiring modelling of all possible viable combinations of field or reservoir and IOR technique.

Therefore it is necessary to identify the most promising projects before embarking on detailed appraisal. In the past, IOR techniques have been screened using simple technical screening criteria based on reservoir depth, oil viscosity, and rock permeability etc. However, this approach gives no indication of the amount of incremental oil that might be recovered or the economic viability. Also, the screening criteria themselves are often based on US onshore experience, and may not be relevant elsewhere in the world or offshore.

To provide a realistic way of evaluating the economic IOR potential in a large number of fields on a practical time scale, ECL Technology has developed the MAESTRO approach that combines analytical evaluation procedures and simple 3-D sector models. The tool is based on two decades of accumulated experience in IOR research and assessments, and enables field portfolios to be assessed at any stage of development from appraisal to mature status. Our Maestro consultancy service is appropriate for clients wishing to screen a single reservoir or a portfolio of fields, either to make general development decisions or to take advantage of particular economic or environmental factors, such as the utilisation of stranded gas or CO2 disposal.

Benefits

• Efficient screening of field portfolios
• Assessment of new and mature fields
• Systematic approach across all IOR techniques/reservoirs

The MAESTRO Methodology

The following techniques are normally considered (although evaluation procedures for other processes, such as polymer gel treatments and post waterflood depressurisation are also available:

• WAG (normally miscible or multi-contact miscible)
• Crestal gas injection (immiscible or miscible gravity segregated gas injection)
• Polymer flooding
• Surfactant flooding

For the gas processes, nitrogen, air, flue gas, lean hydrocarbon gas (essentially methane), carbon dioxide and enriched hydrocarbon gas are considered where appropriate.
An understanding of the field geology and geometry is acquired through discussions with the client and field and economic data are gathered (normally requiring a minimum of ½ day per field).
The MAESTRO tool determines a suite of Performance Indicators for each IOR technique. These provide an understanding of the IOR targets and an indication of technical viability. Performance Indicators include measures of :

• Frontal Stability
• Thermal Stability
• Miscibility
• Viscous/gravity balance

For each combination of reservoir and IOR technique, MAESTRO also estimates the following:

• Incremental recovery for secondary or tertiary processes
• Discounted costs per incremental barrel
• Technical viability
• Economic viability
• Uncertainty

Application of these evaluation procedures allows projects to be compared consistently across all reservoirs and IOR techniques. This enables the potential benefits of IOR to be appreciated more fully, and resources to be targeted on the most promising projects.

 

For further information regarding this service contact:

Contact:Iorteam	Tel: +44 (0)1305 217438
e-mail: IORteam@ecqc.com